The common data storage devices available in the market include a hard driver disk (HDD), formed by a read-and-write magnetic head and a platter, and a solid state disk (SSD), formed by a memory and a control chip. A storage capacity of a HDD would be normally greater than that of a SSD due to its relatively lower cost. On the other hand, a data access rate of the SSD is several times faster than that of the HDD, and the SSD also has advantages of lower power consumption and being unable to be physically destroyed. Hence, a solid state hybrid drive (SSHD) with a hybrid disk architecture has been introduced to a computer system, where the HDD is configured as a basic data storage space, and the SSD is configured as a cache space so as to ensure that access rates and storage capacities both satisfy the user's requirement.
However, the HDD in the SSHD only provides limited storage capacities, and thus how to effectively allocate data storage spaces to let the user feel the advantages of the SSD would be one of the primary concerns for the product developers.